TiO2 seed-assisted growth of VO2(M) films and thermochromic performance

Abstract

This paper reports the TiO₂ seed-assisted hydrothermal growth of VO₂ films on a quartz substrate. The rutile TiO₂ seed layer can promote the oriented growth of VO₂(M) at the initial stage of the hydrothermal reaction, and then, the VO₂(D) phase further grows on top of the VO₂(M) layer. It was found that a pure VO₂(M) thin film can grow on the TiO₂ seed layer at a temperature as low as 200 °C. A subsequent annealing treatment can transform the VO₂(D) phase to the VO₂(M) phase. The VO₂(M)/TiO₂ composite films display thickness-dependent optical and electrical performance, and nearly 55% infrared modulation at 3 μm and 3 orders of magnitude resistance modulation can be realized. Our results demonstrate important progress in growth of VO₂(M) thermochromic thin films, which will find potential application in constructing VO₂-based switching devices.